Devices including memory arrays, row decoder circuitries and column decoder circuitries

ABSTRACT

Some embodiments include a device having an array of memory cells, a memory control unit at least partially under the array, row decoder circuitry in data communication with the memory control unit, and column decoder circuitry in data communication with the memory control unit. Some embodiments include a device having an array of memory cells, row decoder circuitry and column decoder circuitry. One of the row and column decoder circuitries is within a unit that extends at least partially under the array of memory cells and the other within a unit that is laterally outward of the array of memory cells.

RELATED PATENT DATA

This patent resulted from a divisional of U.S. patent application Ser.No. 14/657,252, which was filed Mar. 13, 2015 and which is incorporateby reference herein.

TECHNICAL FIELD

Devices including memory arrays, row decoder circuitries and columndecoder circuitries.

BACKGROUND

Memory provides data storage for electronic systems. Flash memory is onetype of memory, and has numerous uses in modern computers and devices.For instance, modern personal computers may have BIOS stored on a flashmemory chip. As another example, it is becoming increasingly common forcomputers and other devices to utilize flash memory in solid statedrives to replace conventional hard drives. As yet another example,flash memory is popular in wireless electronic devices because itenables manufacturers to support new communication protocols as theybecome standardized, and to provide the ability to remotely upgrade thedevices for enhanced features.

NAND may be a basic architecture of flash memory, and may be configuredto comprise vertically-stacked memory cells. Example NAND architectureis described in U.S. Pat. Nos. 7,898,850 and 8,778,762, and in U.S.Patent Publication Nos. 2014/0191306 and 2014/0131784.

FIG. 1 shows a block diagram of a prior art device 100 which includes amemory array 102 having a plurality of memory cells 103 arranged in rowsand columns along with access lines 104 (e.g., wordlines to conductsignals WL0 through WLm) and first data lines 106 (e.g., bitlines toconduct signals BL0 through BLn). Access lines 104 and first data lines106 may be used to transfer information to and from the memory cells103. Row decoder circuitry 107 and column decoder circuitry 108 decodeaddress signals A0 through AX on address lines 109 to determine whichones of the memory cells 103 are to be accessed. Driver circuitry 91 maybe utilized in conjunction with the row decoder circuitry to drive aselected wordline 104, and similarly driver circuitry 93 may be utilizedin conjunction with the column decoder circuitry to drive a selecteddata line 106. A sense amplifier circuit 115 operates to determine thevalues of information read from the memory cells 103. An I/O circuit 117transfers values of information between the memory array 102 andinput/output (I/O) lines 105. Signals DQ0 through DQN on the I/O lines105 can represent values of information read from or to be written intothe memory cells 103. Other devices can communicate with the device 100through the I/O lines 105, the address lines 109, or the control lines120. A memory control unit 118 controls memory operations to beperformed on the memory cells 103 utilizing signals on the control lines120. The device 100 can receive supply voltage signals Vcc and Vss on afirst supply line 130 and a second supply line 132, respectively. Thefirst and second supply lines 130 and 132 may be coupled with a powermanagement circuit 95. Also, other components of device 100 may becoupled with the power management circuit, although such electricalcouplings are not specifically shown in FIG. 1.

The device 100 includes a select circuit 140 which may be utilized withthe input/output (I/O) circuit 117. The select circuit 140 can respond,via the I/O circuit 117, to signals CSEL1 through CSELn to selectsignals on the first data lines 106 and the second data lines 113 thatcan represent the values of information to be read from or to beprogrammed into the memory cells 103. The column decoder circuitry 108can selectively activate the CSEL1 through CSELn signals based on the A0through AX address signals on the address lines 109. The select circuit140 can select the signals on the first data lines 106 and the seconddata lines 113 to provide communication between the memory array 102 andthe I/O circuit 117 during read and programming operations.

FIG. 2 shows a block diagram of a prior art memory array (e.g., thememory array 102 of FIG. 1) in the form of a 3D NAND memory device 200.The device 200 may comprise a plurality of strings of charge storagedevices. In a first (e.g., Z-Z′) direction, each string of chargestorage devices may comprise, for example, thirty two charge storagedevices stacked over one another with each charge storage devicecorresponding to one of, for example, thirty two tiers (e.g.,Tier0-Tier31). The charge storage devices of a respective string mayshare a common channel region, such as one formed in a respective pillarof semiconductor material (e.g., polysilicon) about which the string ofcharge storage devices are formed. In a second (e.g., X-X′) direction,each first group of, for example, sixteen first groups of the pluralityof strings may comprise, for example, eight strings sharing a plurality(e.g., thirty two) of access lines (WLs). Each of the plurality ofaccess lines (hereinafter used interchangeably with “global control gate(CG) lines”) may couple (e.g., electrically or otherwise operablyconnect) the charge storage devices corresponding to a respective tierof the plurality of tiers of each string of a corresponding one of thefirst groups. The charge storage devices coupled by the same access line(and thus corresponding to the same tier) may be logically grouped into,for example, two pages, such as P0/P32, P1/P33, P2/P34 and so on, wheneach charge storage device comprises a multi-level cell capable ofstoring two bits of information. In a third (e.g., Y-Y′) direction, eachsecond group of, for example, eight second groups of the plurality ofstrings may comprise sixteen strings coupled by a corresponding one ofeight data lines (BLs). The CGs of the (e.g., sixteen) charge storagedevices corresponding to a respective tier of the (e.g., sixteen)strings of each second group of strings may be physically coupled by arespective plate. Similarly, SGSs of the (e.g., sixteen) strings of eachsecond group of strings may be physically coupled by a single plate. Thesize of a memory block may comprise 1,024 pages and total about 16 MB(e.g., 16 WLs×32 Tiers×2 bits=1,024 pages/block, block size=1,024pages×16 KB/page=16 MB). The number of the strings, tiers, access lines,data lines, first groups, second groups and/or pages may be greater orsmaller than those shown in FIG. 2.

FIG. 3 shows a cross-sectional view of a memory block 300 of the 3D NANDmemory device 200 of FIG. 2 in an X-X′ direction, including fifteenstrings of charge storage devices in one of the sixteen first groups ofstrings described with respect to FIG. 2. The plurality of strings ofthe memory block 300 may be grouped into a plurality of subsets 310,320, 330 (e.g., tile columns), such as tile column_(l), tile column_(j)and tile column_(K), with each subset (e.g., tile column) comprising a“partial block” of the memory block 300. A global drain-side select gate(SGD) line 340 may be coupled to the SGDs of the plurality of strings.For example, the global SGD line 340 may be coupled to a plurality(e.g., three) of sub-SGD lines 342, 344, 346 with each sub-SGD linecorresponding to a respective subset (e.g., tile column), via acorresponding one of a plurality (e.g., three) of sub-SGD drivers 332,334, 336. Each of the sub-SGD drivers 332-336 may concurrently couple orcut off the SGDs of the strings of a corresponding partial block (e.g.,tile column) independently of those of other partial blocks. A globalsource-side select gate (SGS) line 360 may be coupled to the SGSs of theplurality of strings. For example, the global SGS line 360 may becoupled to a plurality of sub-SGS lines 362, 364, 366 with each sub-SGSline corresponding to the respective subset (e.g., tile column), via acorresponding one of a plurality of sub-SGS drivers 322, 324, 326. Eachof the sub-SGS drivers 322, 324, 326 may concurrently couple or cut offthe SGSs of the strings of a corresponding partial block (e.g., tilecolumn) independently of those of other partial blocks. A global accessline (e.g., a global CG line) 350 may couple the charge storage devicescorresponding to the respective tier of each of the plurality ofstrings. Each global CG line (e.g., the global CG line 350) may becoupled to a plurality of sub-access lines (e.g., sub-CG lines) 352,354, 356 via a corresponding one of a plurality of sub-string drivers312, 314 and 316. Each of the sub-string drivers may concurrently coupleor cut off the charge storage devices corresponding to the respectivepartial block and/or tier independently of those of other partial blocksand/or other tiers. The charge storage devices corresponding to therespective subset (e.g., partial block) and the respective tier maycomprise a “partial tier” (e.g., a single “tile”) of charge storagedevices. The strings corresponding to the respective subset (e.g.,partial block) may be coupled to a corresponding one of sub-sources 372,374 and 376 (e.g., “tile source”) with each sub-source being coupled toa respective power source.

FIG. 4 shows a region of a prior art semiconductor wafer. Such region issubdivided amongst a plurality of individual die 400. The die may all besubstantially identical to one another, and ultimately the die may besingulated into individual units suitable for incorporation intoindividual packages. For instance, each die may correspond to a memorychip.

FIG. 5 shows an example singulated die 400 from the region identified asregion 5 of FIG. 4. The illustrated die 400 comprises a memory arrayregion 102 (also identified as the Array (A)), row decoder circuitry 107(also identified as Row (R)), column decoder circuitry 108 (alsoidentified as Col (C)), a peripheral region 412 (also identified as Peri(P)), and a bonding pad region 414 (also identified as Bonding Pad (B)).Additionally, a memory control unit (MCU) 118 is shown to be within theperipheral region 412.

The die of FIG. 5 may be considered to be an example of atwo-dimensional arrangement, in that no components are stacked under thearray 102. In contrast, FIG. 6 shows a prior art die 400 a illustratingan example three-dimensional arrangement. The array 102 is dividedamongst a plurality of tiles (T) 420, and each tile has column decodercircuitry (C) 108 and row decoder circuitry (R) 107 under the array 102,(the regions 107 and 108 are shown in phantom view relative to one ofthe tiles to indicate that they are under the array region). Also,drivers (D) 91/93 are within each tile and under the array region.

The configuration of FIG. 6 advantageously saves die area by stackingthe row and column decoder circuitries under the array. The tiles may beutilized in an effort to reduce wordline resistance and/or bitlineresistance across an array while maintaining desired access speeds.However, the tile configuration introduces additional complications andassociated expenses into die fabrication and array programming. It isdesired to develop new arrangements of various components of memorychips which save die area, and which enable desired access speeds to beachieved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a block diagram of a prior art memory device having amemory array with memory cells.

FIG. 2 shows a schematic diagram of the prior art memory array of FIG. 1in the form of a 3D NAND memory device.

FIG. 3 shows a cross sectional view of the prior art 3D NAND memorydevice of FIG. 2 in an X-X′ direction.

FIG. 4 is a diagrammatic view of a region of a prior art semiconductorwafer.

FIGS. 5 and 6 are diagrammatic views of example prior art semiconductordies.

FIGS. 7-12 are diagrammatic views of example dies illustrating examplearrangements of various components in accordance with exampleembodiments.

FIGS. 7A and 8A are diagrammatic cross-sectional views along the lines7A-7A and 8A-8A of FIGS. 7 and 8, respectively.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Some embodiments include recognition that it may be advantageous toplace one or more components normally associated with peripheralcircuitry under an array of memory cells in order to increase packingdensity within a semiconductor die. For instance, it may be advantageousto place the memory control unit, the power management circuit, the I/Ocircuit, and/or the sense amplifiers under the memory array. Inconventional die fabrication, it is often not feasible to placeperipheral circuit components under the memory array due to thesubdivision of the array within tile architecture. However, someembodiments recognize that it may be possible to eliminate the tilearchitecture by changing bitline/wordline materials to lower resistancematerials, reducing the size of the memory array, etc.

Some embodiments include recognition that it may be advantageous to haveone of the row/column decoder circuitries under a memory array and theother of the row/column decoder circuitries laterally adjacent to thememory array. Such embodiments may be effective in non-tiledarchitectures, and may even have application to some tiledarchitectures.

Example embodiments are described with reference to FIGS. 7-12.

FIGS. 7 and 7A show a die 10 in accordance with an example embodiment.The illustrated die is a singulated die. However, it is to be understoodthat the die 10 may be also be one of a plurality of dice associatedwith a wafer analogous to the dice 400 described above with reference toFIG. 4.

The die 10 comprises an array (A) 102. The array is an array of memorycells, and in some embodiments may be an array of NAND memory cells. Inother embodiments, the array may comprise any other suitable memorycells.

A pair of decoder circuitries D₁ and D₂ are provided proximate thearray. One of the decoder circuitries corresponds to row decodercircuitry 107 and the other corresponds to column decoder circuitry 108.The decoder circuitries are generically labeled 107/108 in FIG. 7. Thedecoder circuitry D₁ is within a single unit 15 under the array 102, andthe decoder circuitry D₂ is within a single unit 17 laterally adjacentto the array. The units 15 and 17 may be referred to as first and secondunits, respectively.

Although the unit 15 of decoder circuitry D₁ is shown to be entirelyunder the array, in other embodiments the unit of decoder circuitry maybe configured to have only a portion directly under the array and tohave another portion which is not directly under the array (forinstance, in embodiments analogous to those described below withreference to FIGS. 9 and 12).

A bonding pad 20 is adjacent to the array. The bonding pad 20 may beanalogous to the bonding pad 414 described above with reference to FIG.5.

Peripheral circuitry 30 is under the array and laterally adjacent to thedecoder circuitry D₁. The peripheral circuitry includes circuitry otherthan the array of memory cells, and the row and column decodercircuitries. The peripheral circuitry under the array may comprise anyof numerous components, including, for example, the memory control unit(118 of FIG. 1), the power management unit (95 of FIG. 1), the I/Ocircuit (117 of FIG. 1), etc. Additional peripheral circuitry (notshown) may be laterally adjacent to the array. In some embodiments, aunit comprised by the peripheral circuitry may be entirely under thearray, and in other embodiments may be only partially under the array.For instance, in some embodiments a memory control unit may be entirelyunder the array, and in other embodiments only a portion of the memorycontrol unit may be under the array.

In some embodiments, D₁ is row decoder circuitry, and row drivercircuitry (91 of FIG. 1) is under the array 102 together with thedecoder circuitry D₁.

In some embodiments, D₁ is column decoder circuitry, and one or more ofcolumn driver circuitry (93 of FIG. 1), I/O circuitry (117 of FIG. 1)and sense amplifier circuitry (115 of FIG. 1) is under the array 102together with the decoder circuitry D₁.

FIG. 7A is a cross-sectional view of die 10, and shows a base 12supporting the various components. The base 12 may comprisesemiconductor material, and in some embodiments may comprise, consistessentially of, or consist of monocrystalline silicon. In someembodiments, base 12 may be considered to comprise a semiconductorsubstrate. The term “semiconductor substrate” means any constructioncomprising semiconductive material, including, but not limited to, bulksemiconductive materials such as a semiconductive wafer (either alone orin assemblies comprising other materials), and semiconductive materiallayers (either alone or in assemblies comprising other materials). Theterm “substrate” refers to any supporting structure, including, but notlimited to, the semiconductor substrates described above. In someembodiments, base 12 may correspond to a semiconductor substratecontaining one or more materials associated with integrated circuitfabrication. Some of the materials may be under the shown region of base12 and/or may be laterally adjacent to the shown region of base 12; andmay correspond to, for example, one or more of refractory metalmaterials, barrier materials, diffusion materials, insulator materials,etc.

The decoder circuitry D₁ and the peripheral circuitry 30 are shown to bedirectly under the array 102, and are contained within insulativematerial 34. The insulative material 34 may comprise any suitablematerial, including, for example, one or more of silicon dioxide,silicon nitride, borophosphosilicate glass, etc. Although the decodercircuitry D₁ and the peripheral circuitry 30 are both shown to be spacedfrom base 12 by insulative material 34, in other embodiments one or bothof the decoder circuitry D₁ and the peripheral circuitry 30 may be alongan upper surface of base 12. Also, although the decoder circuitry D₁ andthe peripheral circuitry 30 are both shown to be at a same elevationallevel as one another above base 12, in other embodiments they may be atdifferent elevational levels relative to one another.

The decoder circuitry D₁ and the peripheral circuitry 30 may compriseany suitable circuit components, and in some embodiments one or both ofthe decoder circuitry D₁ and the peripheral circuitry 30 may compriseone or more transistor gates.

The bond pad 20 is shown to be supported over insulative material 34,and to be electrically coupled to base 12 through an interconnectingwire 21. The illustrated connection to base 12 is an example connection,and the bond pad may have any suitable connections to any circuitriesassociated with die 10. For instance, in some embodiments the bond padmay have electrical connections to one or more of the circuitriescorresponding to the array, the periphery, and the decoders D₁ and D₂;either in addition to, or alternatively to, the illustrated electricalconnection to base 12.

Referring to FIG. 7, conductive line 23 extends from decoder circuitryD₂ across the array 102, and conductive line 25 extends from decodercircuitry D₁ across the array. The conductive lines 23 and 25 areexamples of wordlines and bitlines that may extend across the array. Thewordlines extend from the row decoder, and the bitlines extend from thecolumn decoder. Notably, the conductive line 25 extends past the arrayto electrically connect with the decoder circuitry D₁. This is due tothe decoder circuitry D₁ being under the array. In other embodiments,other methods of connecting conductive line 25 to the decoder circuitryD₁ may be utilized.

The footprint comprised by the illustrated components of die 10 of FIG.7 may be smaller than the footprint comprised by similar components ofthe prior art die 400 of FIG. 5. Notably, the footprint of die 10comprises the area of the array 102, together with the areas of thedecoder D₂ and the bonding pad 20. In contrast, the footprint of die 400comprises the area of the array together with areas of the bonding pad,both of the row and column decoders, and the periphery 118. Accordingly,the configuration of the die 10 of FIG. 7 may advantageously enable alarger number of dice to be formed from a single wafer than can beaccomplished utilizing the prior art die 400 of FIG. 5. Further, the die10 of FIG. 7 does not have a tiled architecture, which can simplifyprocessing and reduce expense of fabrication of the die 10 of FIG. 7relative to the prior art die of FIG. 6.

FIGS. 8 and 8A show a die 10 a illustrating an embodiment similar tothat of FIG. 7, but in which the first unit 15 specifically correspondsto column decoder circuitry (C) 108, and in which the second unit 17specifically corresponds to row decoder circuitry (R) 107. In theembodiment of FIG. 8, the conductive line 23 is a wordline, and theconductive line 25 is a bitline. A memory control unit 118, a powermanagement circuit 95, an I/O circuit 117 and a sense amplifier circuit115 are specifically illustrated to be part of the peripheral circuitry30 that is under the array 102. In other embodiments, the peripheralcircuitry 30 may comprise other components in addition to the showncomponents 118, 95, 117 and 115; or may comprise less than all of theshown components 118, 95, 117 and 115.

The array 102 is shown to have a rectangular configuration with fourprimary sides 7, 9, 11 and 13. In the illustrated embodiment, thebonding pad 20 is along a first of the primary sides (specifically side9) and the unit 17 of row decoder circuitry 107 is along another of theprimary sides (specifically side 11) which is adjacent to the firstprimary side.

The footprint of die 10 a of FIG. 8 comprises the area of the array 102,together with the areas of the row decoder circuitry 107 and the bondingpad 20. In contrast, the footprint of the prior art die 400 of FIG. 5comprises the area of the array together with areas of the bonding pad,both of the row and column decoders, and the periphery 118. Accordingly,the configuration of the die 10 a of FIG. 8 may advantageously enable alarger number of dice to be formed from a single wafer than can beaccomplished utilizing the prior art die 400 of FIG. 5. Further, the die10 a of FIG. 8 does not have a tiled architecture, which can simplifyprocessing and reduce expense of fabrication of the die 10 a of FIG. 8relative to the prior art die of FIG. 6.

The embodiment of FIG. 8 shows the column decoder unit 15 under thearray 102 to be adjacent one of the edges of the array. Such requiresfabrication of bitlines 25 which extend a full dimension of the array.Depending on the size of the array and the resistance of the materialutilized for the bitlines, there may be difficulties in configuring thebitlines while also maintaining low enough resistance to enable desiredperformance characteristics. FIG. 9 shows a die 10 b illustrating analternative arrangement in which the column decoder 15 under the arrayis provided as a single unit centrally located relative to the array.The array is subdivided into two units A₁ and A₂. In the shownembodiment, both units are approximately the same size as one another,which may be preferred in some applications in that it provides similaraccess times across the entirety of the array. However, in otherembodiments one of the units A₁ and A₂ may be of a different sizerelative to the other. The units A₁ and A₂ may be considered to beportions of a single array in some embodiments, and in other embodimentsmay be considered to correspond to two different arrays of memory cells.

The column decoder circuitry 108 is configured as a single unit 15having outer edges 31 that are directly under the array 102 of memorycells (with the outer edges being shown in phantom view to indicate thatthey are beneath array 102), and having a central region 33 which is notdirectly under the array.

The centralized location of column decoder circuitry 108 under the array102 enables the long bitline 25 (FIG. 8) to be replaced with shorterbitlines 25 a and 25 b. This may enable desired performancecharacteristics to be achieved with higher resistance bitline materialsas compared to the bitline materials suitable for utilization in theembodiment of FIG. 8.

A memory control unit 118 is specifically illustrated to be part of theperipheral circuitry 30 that is under the array 102 of FIG. 9. In otherembodiments, the peripheral circuitry 30 may comprise other componentsin addition to, or alternatively to, the shown component 118.

A cross-sectional side view of FIG. 9 is not provided, but such may besimilar to the views of FIGS. 7A and 8A.

The footprint of die 10 b of FIG. 9 comprises the area of the array 102,together with the areas of the row decoder circuitry 107, the bondingpad 20 and a portion of column decoder circuitry 108. In contrast, thefootprint of the prior art die 400 of FIG. 5 comprises the area of thearray together with areas of the bonding pad, both of the row and columndecoders, and the periphery 118. Accordingly, the configuration of thedie 10 b of FIG. 9 may advantageously enable a larger number of dice tobe formed from a single wafer than can be accomplished utilizing theprior art die 400 of FIG. 5. Further, the die 10 b of FIG. 9 does nothave a tiled architecture, which can simplify processing and reduceexpense of fabrication of the die 10 b of FIG. 9 relative to the priorart die of FIG. 6.

FIG. 10 shows a die 10 c illustrating an example configuration in whichcolumn decoder circuitry 108 is within a unit 15 laterally adjacent tothe array 102 of memory cells, and in which the row decoder circuitry107 is within a unit 17 under the array of memory cells. The wordline 23of FIG. 10 now extends beyond the decoder circuitry 107 so that lateralcontact may be made between the decoder circuitry and the array. Inother embodiments, other methods may be utilized to achieve electricalconnection between the array and the decoder circuitry 107 underneaththe array.

In the illustrated embodiment of FIG. 10, the bonding pad 20 is alongthe first primary side 9 of the rectangular array 102 and the unit 15 ofcolumn decoder circuitry 108 is along another of the primary sides(specifically side 13) which is in opposing relation to the firstprimary side.

A memory control unit 118 is specifically illustrated to be part of theperipheral circuitry 30 that is under the array 102 of FIG. 10. In otherembodiments, the peripheral circuitry 30 may comprise other componentsin addition to, or alternatively to, the shown component 118.

The footprint of die 10 c of FIG. 10 comprises the area of the array102, together with the areas of the column decoder circuitry 108 and thebonding pad 20. In contrast, the footprint of the prior art die 400 ofFIG. 5 comprises the area of the array together with areas of thebonding pad, both of the row and column decoders, and the periphery 118.Accordingly, the configuration of the die 10 c of FIG. 10 mayadvantageously enable a larger number of dice to be formed from a singlewafer than can be accomplished utilizing the prior art die 400 of FIG.5. Further, the die 10 c of FIG. 10 does not have a tiled architecture,which can simplify processing and reduce expense of fabrication of thedie 10 c of FIG. 10 relative to the prior art die of FIG. 6.

A cross-sectional side view of FIG. 10 is not provided, but such may besimilar to the views of FIGS. 7A and 8A.

Referring to FIG. 11, a die 10 d illustrates an example configuration inwhich the row decoder circuitry 107 is divided amongst two units 17 a(also labeled R₁) and 17 b (also labeled R₂) that are on opposing sidesof the array 102 relative to one another. The utilization of two unitsof decoder circuitry may enable shorter wordlines 23 a and 23 b to beutilized relative to the embodiment of FIG. 10. This may enable desiredperformance characteristics to be achieved with higher resistancewordline materials as compared to the wordline materials suitable forutilization in the embodiment of FIG. 10.

A memory control unit 118 is specifically illustrated to be part of theperipheral circuitry 30 that is under the array 102 of FIG. 11. In otherembodiments, the peripheral circuitry 30 may comprise other componentsin addition to, or alternatively to, the shown component 118.

The footprint of die 10 d of FIG. 11 comprises the area of the array102, together with the areas of the column decoder circuitry 108 and thebonding pad 20. In contrast, the footprint of the prior art die 400 ofFIG. 5 comprises the area of the array together with areas of thebonding pad, both of the row and column decoders, and the periphery 118.Accordingly, the configuration of the die 10 d of FIG. 11 mayadvantageously enable a larger number of dice to be formed from a singlewafer than can be accomplished utilizing the prior art die 400 of FIG.5. Further, the die 10 d of FIG. 11 does not have a tiled architecture,which can simplify processing and reduce expense of fabrication of thedie 10 d of FIG. 11 relative to the prior art die of FIG. 6.

A cross-sectional side view of FIG. 11 is not provided, but such may besimilar to the views of FIGS. 7A and 8A.

The row decoder circuitry 107 is subdivided amongst two units in theembodiment of FIG. 11. In other embodiments (not shown), the columndetector circuitry 108 may be analogously subdivided. Also, althoughsubdivision into two units is illustrated, in other embodiments thesubdivision may be into more than two units.

The embodiment of FIG. 10 shows the row decoder unit 17 under the array102 to be adjacent to one of the edges of the array. Such requiresfabrication of wordlines 23 which extend a full dimension of the array.Depending on the size of the array and the resistance of the materialutilized for the wordlines, there may be difficulties in configuring thewordlines while also maintaining low enough resistance to enable desiredperformance characteristics. FIG. 12 shows a die 10 e illustrating analternative arrangement in which the row decoder 17 under the array isprovided as a single unit centrally located relative to the array. Thearray is subdivided into two units A₁ and A₂. In the shown embodiment,both units are approximately the same size as one another, which may bepreferred in some applications in that it provides similar access timesacross the entirety of the array. However, in other embodiments one ofthe units A₁ and A₂ may be of a different size relative to the other.The units A₁ and A₂ may be considered to be portions of a single arrayin some embodiments, and in other embodiments may be considered tocorrespond to two different arrays of memory cells.

The row decoder circuitry 107 is configured as a single unit 17 havingouter edges 41 that are directly under the array 102 of memory cells(with the outer edges being shown in phantom view to indicate that theyare beneath array 102), and having a central region 43 which is notdirectly under the array.

The centralized location of row decoder circuitry 107 under the array102 enables the long wordline 23 (FIG. 10) to be replaced with shorterwordlines 23 a and 23 b. This may enable desired performancecharacteristics to be achieved with higher resistance wordline materialsas compared to the wordline materials suitable for utilization in theembodiment of FIG. 10.

In the shown embodiment, the periphery is subdivided into two units P₁and P₂. Both periphery units are shown to approximately the same size asone another, which may be preferred in some applications. However, inother embodiments one of the units P₁ and P₂ may be of a different sizerelative to the other. The units P₁ and P₂ may be connected to oneanother through wiring provided in an interconnect region 45.

Bitlines 25 a and 25 b are shown in FIG. 12 to extend across array 102from column decoder circuitry 108.

A memory control unit 118 is specifically illustrated to be part of theperipheral circuitry 30 that is under the array 102 of FIG. 12. In otherembodiments, the peripheral circuitry 30 may comprise other componentsin addition to, or alternatively to, the shown component 118.

The footprint of die 10 e of FIG. 12 comprises the area of the array102, together with the areas of the column decoder circuitry 108, thebonding pad 20, and a portion of row decoder circuitry 107. In contrast,the footprint of the prior art die 400 of FIG. 5 comprises the area ofthe array together with areas of the bonding pad, both of the row andcolumn decoders, and the periphery 118. Accordingly, the configurationof the die 10 d of FIG. 11 may advantageously enable a larger number ofdice to be formed from a single wafer than can be accomplished utilizingthe prior art die 400 of FIG. 5. Further, the die 10 e of FIG. 12 doesnot have a tiled architecture, which can simplify processing and reduceexpense of fabrication of the die 10 e of FIG. 12 relative to the priorart die of FIG. 6.

Although the specific embodiments of FIGS. 7-12 pertain to non-tiledarchitectures, in other embodiments some aspects may be incorporatedinto tiled architectures analogous to the architecture of FIG. 6. Forinstance, in some embodiments tiled architectures may be formed to haveone of the row and column detectors at least partially under a memoryarray and the other laterally adjacent to the memory array.

The architectures described herein may be used in chips that areincorporated into in any of a broad range of systems, such as, forexample, clocks, televisions, cell phones, personal computers,automobiles, industrial control systems, aircraft, etc.

Unless specified otherwise, the various materials, substances,compositions, etc. described herein may be formed with any suitablemethodologies, either now known or yet to be developed, including, forexample, atomic layer deposition (ALD), chemical vapor deposition (CVD),physical vapor deposition (PVD), etc.

The particular orientation of the various embodiments in the drawings isfor illustrative purposes only, and the embodiments may be rotatedrelative to the shown orientations in some applications. The descriptionprovided herein, and the claims that follow, pertain to any structuresthat have the described relationships between various features,regardless of whether the structures are in the particular orientationof the drawings, or are rotated relative to such orientation.

The cross-sectional views of the accompanying illustrations only showfeatures within the planes of the cross-sections, and do not showmaterials behind the planes of the cross-sections in order to simplifythe drawings.

When a structure is referred to above as being “on” or “against” anotherstructure, it can be directly on the other structure or interveningstructures may also be present. In contrast, when a structure isreferred to as being “directly on” or “directly against” anotherstructure, there are no intervening structures present. When a structureis referred to as being “connected” or “coupled” to another structure,it can be directly connected or coupled to the other structure, orintervening structures may be present. In contrast, when a structure isreferred to as being “directly connected” or “directly coupled” toanother structure, there are no intervening structures present.

Some embodiments include a device comprising an array of memory cells, amemory control unit at least partially under the array, row decodercircuitry in data communication with the memory control unit, and columndecoder circuitry in data communication with the memory control unit.

Some embodiments include a device comprising an array of memory cells,D₁ decoder circuitry and D₂ decoder circuitry. One of the D₁ and D₂decoder circuitries is in a first unit corresponding to row decodercircuitry and the other is in a second unit corresponding to columndecoder circuitry. One of the first and second units is at leastpartially under the array of memory cells and the other of the first andsecond units is laterally outward of the array of memory cells.

Some embodiments include a device comprising an array of memory cells,column decoder circuitry at least partially under the array of memorycells, row decoder circuitry laterally outward of the array of memorycells, a memory control unit at least partially under the array ofmemory cells, and a bonding pad region laterally outward of the array ofmemory cells.

Some embodiments include a device comprising an array of memory cells,row decoder circuitry at least partially under the array of memorycells, column decoder circuitry laterally outward of the array of memorycells, a memory control unit at least partially under the array ofmemory cells, and a bonding pad region laterally outward of the array ofmemory cells.

In compliance with the statute, the subject matter disclosed herein hasbeen described in language more or less specific as to structural andmethodical features. It is to be understood, however, that the claimsare not limited to the specific features shown and described, since themeans herein disclosed comprise example embodiments. The claims are thusto be afforded full scope as literally worded, and to be appropriatelyinterpreted in accordance with the doctrine of equivalents.

I claim:
 1. A device, comprising: an array of memory cells disposed at afirst level above a base; row decoder circuitry disposed at a secondlevel above the base, the second level being elevationally below thefirst level, the row decoder circuitry consisting of a single unit andbeing entirely under the array of memory cells; column decoder circuitrydisposed at the first level laterally outward of the array of memorycells; peripheral circuitry disposed at the second level and comprisinga memory control unit entirely under the array of memory cells; and abonding pad region disposed at the first level laterally outward of thearray of memory cells.
 2. The device of claim 1 wherein the single unitof row decoder circuitry is centrally located under the array of memorycells.
 3. The device of claim 1 wherein the single unit of row decodercircuitry is not centrally located under the array of memory cells. 4.The device of claim 1 wherein the bonding pad region is on an opposingside of the array of memory cells from the column decoder circuitry. 5.A device, comprising: a semiconductor die having a first level and asecond level elevationally above the first level, the die comprising: anarray of memory cells within the second level; column decoder circuitrywithin the second level laterally outward of the array of memory cells;peripheral circuitry divided into a first unit and a second unit, eachof the first and second units being within the first level and beingentirely under the array of memory cells; row decoder circuitry disposedwithin the first level between the first and second units of peripheralcircuitry, and being disposed at least partially under the array ofmemory cells; and a bonding pad region laterally outward of the array ofmemory cells.
 6. The device of claim 5 wherein the array of memory cellsdivided into two units is of memory cells, wherein the row decodercircuitry consists of a single unit disposed between the two arrays ofmemory cells, and wherein the single unit of row decoder circuitry hasedge regions extending under each of the two units of memory cells andhas a central region that is not directly under either of the arrays ofmemory cells.
 7. The device of claim 5 wherein the row decoder circuitryis entirely under the array of memory cells.
 8. A device, comprising: asemiconductor die having a first level and a second level elevationallyabove the first level; an array of memory cells within the second level;decoder circuitry comprising row decoder circuitry consisting of asingle unit entirely within the first level and disposed entirely underthe array of memory cells, and column decoder circuitry consisting of asingle unit, the column decoder circuitry being entirely disposed withinthe second level on a first side of the array of memory cells; a bondingpad disposed along a second side of the array of memory cells, thesecond side opposing the first side; and a memory control unit disposedat least partially under the array of memory cells and within the firstlevel.
 9. The device of claim 8 wherein the memory control unit isdisposed entirely under the memory array.
 10. The device of claim 8comprising a wordline that extends beyond lateral boundaries of thedecoder circuitry, the wordline providing lateral contact between thedecoder circuitry and the array of memory cells.